ImmunoGen has reported positive clinical data with IMGN901 candidate in the treatment of relapsed and relapsed/refractory multiple myeloma (MM), including prolonged benefit in patients whose disease had progressed on multiple prior treatment regimens.
IMGN901 is an investigational agent designed to kill cancer cells that express CD56, a protein. It consists of a CD56-binding antibody with a potent cancer-cell killing agent, DM1, attached to it using an engineered linker. IMGN901 is in Phase I testing for the treatment of CD56-expressing solid tumors and multiple myeloma. It is wholly-owned by ImmunoGen.
In the trial, new cohorts of patients received increasingly greater amounts of IMGN901 – used as a single agent – until the maximum tolerated dose was established. All of the patients had CD56-expressing MM that had progressed on multiple therapies, and most had previously been treated with at least six chemotherapy regimens.
Reportedly, among the 26 patients treated with IMGN901 at any dose level, the overall clinical benefit rate (objective responses plus sustained stable disease) was 46%. Typically in the treatment of cancer, patients have their best treatment responses early in the course of their disease and respond less well to later therapies.
The study results suggested that IMGN901 was found to be generally well tolerated and was not associated with significant myelosuppression or other side effects that would limit its ability to be administered in combination with other active agents.
James O’Leary, vice president and chief medical officer of ImmunoGen, said: “This trial – Study 003 – has provided us with important information on the safety of IMGN901 when used alone to treat multiple myeloma that has progressed on numerous prior therapies.
“The expansion phase of this trial, which is now underway, provides for patients with less heavily pretreated multiple myeloma to receive IMGN901 at the maximum tolerated dose, enabling us to better assess its activity when used as a single agent.
“Multiple myeloma is often treated with a combination of therapies with different mechanisms of action. Thus, we feel it’s important to also assess IMGN901 as part of a multi-agent regimen. The profile of IMGN901 suggests that it’s particularly well suited to use in combination, as it works by a novel mechanism and has not been associated with side effects that would limit its ability to be used with other agents. We expect patient dosing in our Study 005 combination trial to begin shortly.”